Cooling & Heating Fundamentals

Anyone who struggles with ill health through their school years, is largely self-taught as a result, yet creates a career for themselves in industry and then transitions to the top flights of academia deserves our respect. When this person works alongside far more famous colleagues, but has his career cut short by ill health and dies at the age of 52, it seems likely they would fade into obscurity. No so for Professor William John Macquorn Rankine, engineer, scientist, educator, communicator and much more.

As a teenager, Rankine attended the University of Edinburgh for two years, leaving at 18 (without a degree) to join a railroad construction company. He worked in Scotland and Ireland during the early 1840s in the first wave of rapid growth of the railroads and also worked on the construction of harbors and waterworks.

He made one of his first engineering break-throughs with an article called "The Fracture of Axles." This article was the first description of the phenomenon that we now call "metal fatigue" and correctly identified it as the cause of several serious railway accidents. It explained the mechanism that caused cracks to form and then grow near square-cut shoulders in the axles. Rankine showed that the form and structure of metal were significant (as every engineering student now knows). The article also disproved the prevailing theory of the time, that these accidents had been inexplicable and unpredictable because the metal just crystallized spontaneously.

In the early 1850s, he worked as a civil engineer on the construction of the main water supply from Loch Katrine to Glasgow, a distance of over 40 miles (64km). This water supply is credited with driving typhoid and cholera out of the city and is still in use today.

In the early 1840s while still developing his career as a young civil engineer, he started making some ground-breaking advances in thermodynamics, approaching the science of heat from the atomic level. Several novel publications resulted in his election to the Fellowship of the Royal Society in 1853, and two years later he accepted the chair of Civil Engineering and Mechanics at Glasgow University in the company of Professors William Thomson (later Lord Kelvin) and James Clerk Maxwell.

Thomson later wrote of Rankine's contribution to the dynamical theory of heat that "even the mere title of his earliest paper on the subject, 'Molecular Vortices,' is an important contribution to physical science." He is credited with writing the first treatise on thermodynamics in the English language and for naming the equivalence of heat and the increase of entropy as the "first and second laws of thermodynamics," although he wasn't the first to describe them.

As an educator, it was said that "all his writings are marked by a power of statement so clear and logical that the reader, even should he fail entirely to follow the demonstrations, cannot but be benefitted in the attempt to master them." I think this was a compliment.

The same commenter, W.J.Millar, a student of Rankine's, also wrote "Rankine's lectures, although simpler than his textbooks, were marked by the same clearness of arrangement and were enforced by his distinct and vigorous enunciation, and admirably illustrated by carefully prepared diagrams." He was responsible for introducing a degree qualification in engineering at Glasgow University, creating the first engineering graduates in the United Kingdom.

Kelvin and Rankin, who worked at the same university at the same time, have given their names to the two scales of absolute temperature (SI and IP, respectively). Rankine is also now widely remembered for first describing the Rankine power cycle, which is known as the organic Rankine cycle system when it uses HFCs.

Spare a thought for Professor Rankine and his legacy on Christmas Eve this year. William J.M. Rankine: born July 5, 1820, died Dec 24, 1872.